Textile cot



Sept. 18, 1956 i J. ROCKOFF 2,763,033

TEXTILE COT Filed Dec. 15, 1952 INVENTOR. JOSEPH ROCKOFF United States atent C TEXTILE COT Joseph Rockotr, Dayton, Ohio, assignor to The Dayton Rubber Company, a corporation of Ohio Application December 13, 1952, Serial No. 325,796 6 Claims. (Cl. 19'143) This invention relates to textile machine units, and more particularly to cots or roll covers for spinning rolls.

A textile roller as used in present day drawing, roving and spinning machines, comprises a metal arbor having a sleeve-like roll cover known as a cot, surrounding the arbor. This cover is made of leather, cork composition, or certain types of rubber compounds.

In the past, most textile cots were made of leather. These cots proved to be not too satisfactory for use on modern machines which work at relatively high speeds, due to poor resistance to lapping-up and eyebrowing and due to their relatively short life. More recently, cots have been made of synthetic materials which show consider'ably longer life than leather, and also possess better resistance to lapping-up and eyebrowing. I

Despite the improved characteristics which have been imparted to textile cots by the use of some of the new types of synthetic rubber, these cots still do not function perfectly under all conditions and for all types of fibers. Some of the newer types of cots, although considerably improved over leather, still exhibit a tendency toward eyebrowing. This condition results from the failure of the cot to carry short fibers or clearer waste to the top clearer in order to gather preper1 Instead, these short fibers collect at the outside edge of the top clearer and hang down over the roll. This condition is called eyebrowing and the mass of fibers which hangs down is called an eyebrow. As the size of the eyebrow increases it will touch the yarn and bunches of short fibers will be pulled into the yarn, thus impairing its quality.

In applicant's prior application Serial No. 270,805, filed February 9, 1952, he has described a novel textile cot having incorporated therein polyvinyl alcohol to effect modification of the drafting properties thereof.

In applica'nts co-pending application Serial No.

299,841, filed July 19, 1952, he has disclosed and 'described another type of improved textile drafting cot composition having incorporated therewith granulated shells of nut-like materials, such as peanut shells or almond shells. Cots made of the compositions referred to in the foregoing co-pending applications have been found to perform extremely well in service and to be highlyresistant to eyebrowing and lapping-up. It has been applicants experience, however, that even improved compositions of the foregoing type will eventually begin to lose their non-eyebrowing characteristics with the result that they will either have to be reground or the covers thereof replaced. Applicant has carried out extensive experiments to improve the surface life of textile cots and prolong the the period of use before lapping-up or eyebrowing begins to occur in such cot.

In accordance with the present invention, applicant has discovered that highly improved characteristics with respect to durability and performance and particularly with respect to resistance to eyebrowing and lapping-up are obtained by incorporating in the cot compound both the polyvinyl alcohol and the ground up nut shells. The resulting product has been found to perform considerably better than the cots made in accordance with the 'prior inventions having either polyvinyl alcohol or ground up nut shells alone as the modifying constituent. The present invention, therefore, is a continuationimpart of my prior application Serial No. 270,805, filedFebru'ary 9,- 1952, and of my prior application Serial No. 299,841,- filed July 19, 1952'. i I s As set forth above, it is therefore an objector the present invention to provide an improved textile r011 cover or cot which will substantially eliminate objection able eyebrowin and will at the same time provide excl= lent wearand resistance to lapping up of fibers.

Other features andadvanta'ges will become more readily apparent in the following description:

As described in the co=pending applications referred to above, applicant has discovered that by the incorporation of either polyvinyl alcohol or ground up shells in a cot composition the basis of which is an oil-resistant synthetic rubber-like material, eyebrowing is substantially eliminated during the useful life of the cot and the cot possesses excellent performance characteristics with respect to endurance and resistance to lapping up. Furthermore, these cots tend to work clearer waste back into the goods so that it is worked into the yarn thus eliminating a waste which would otherwise occur. Polyvinyl alcohol is normally obtained as a solid material and is incorpo rated in the cot compound as a granular material or powder by milling or otherwise, together with the ground shell and other compounding ingredients as normally utilized. The resulting compounded mixture is then extruded in tubular form,- placed on a core, rag wrapped, and vulcanized. Aft'er vulcanization the rag wrap is removed and the resulting product ground to the desired size. Thetube is then cut to the desired length to form colts or roll covers and these are then mounted on the arbor. A finish grind may be used before the 001: is placed in operation A preferred type of synthetic rubber in which thismateri-al is incorporated is an oil-resistant copolymer of the butadiene-acrylic nitrile type also known as Buna-N, Perbunan, GR-A, or by other wellknown terms used in the trade. Although the butadieneacrylic nitrile copolymers are preferred, other oil-resistant types of synthetic ruber, such as the polyhaloprenes (polychloroprene) and the like may be used. As is well known to the ait, polyvinyl alcohol which is referred to herein, is a product obtained by the hydrolysis of polyvinyl acetate. The resulting compound is in the form of a solid gel! which will vary in physical properties depending on the degree of hydrolysis to which the acetate has been subjected. The various conventional types of polyvinyl alcohol ranging from partially hydrolyzed to substantially completely hydrolyzed types have been found to function satisfactorily in applicants composition. The nut shells used must be of a soft, porous and fibrous structure, the most common examples of which are the shells of peanuts and almonds. The proportions of the respective materials which may be used has been found to be quite variable and in fact improved results are obtained even by the use or small amounts of both or the materials referred to. Therefore, the lower limit is that proportion at which a noticeable improvement will result which may be as low as one per cent of each. The upper limit of proportions is also not critical, although as a practical matter it is undesirable to utilize a combined proportion of these materials which would be greater than double the weight of rubber in the compound. A preferred range of proportions is from 10 to 100 parts of the polyvinyl alcohol by weight 'for each 100 parts of the synthetic rubber and from 10 to 100 parts by weight of the ground shell material per 100 parts of synthetic rubber.

In the case of the polyvinyl alcohol the particle size is not critical but large size particles should be avoided 3 in order to insure uniform mixing, preferably a particle size is chosen which will pass through a 60 mesh sieve. In the case of ground nut shell material, the particle size is generally preferred to be in the range of about 20 to 60 mesh, but here too the limiting factor as to size is that which will insure uniform mixing on the mill.

, The appended drawing illustrates a typical cot'construction of the present invention.

In the drawing:

Figure 1 shows a view in elevation partly in cross section of a conventional type of double cot mounted on an arbor.

' Figure 2 illustrates in cross section an enlarged view of a portion of a cross section of the cover shown in Figure 1.

In Figure 1 the double arbor is represented by 10, each side of the arbor having roll covers 11 and 11a mounted thereon. The particles 13 of ground shell material and 14 of polyvinyl alcohol which are embedded in the composition, are exposed at the surface of the roll as shown more clearly in Figure 2.

The following example will illustrate a typical cot compound of the type described above:

Parts by weight Perbunan (74% butadiene 26% acrylonitrile emulnol) The ingredients corresponding to the foregoing recipe were mixed, extruded, vulcanized, and made into cots in the manner described above. The resulting cots were then placed on spinning frames drafting cotton and rayon fibers in comparison with other cots of similar Perbunan compounds, but without both the polyvinyl alcohol and the peanut shell. Cot A was made as above, but elminated the polyvinyl alcohol and contained 50 parts of ground peanut shell per 100 parts by weight of the rubber. Cot B eliminated the peanut shell, but contained 40 parts of polyvinyl alcohol per 100 parts by weight of the rubber. Cot C was made according to the above compound and contained 50 parts of peanut shell and 20 parts of polyvinyl alcohol per 100 parts by weight of the rubber. These cots were placed on spinning and drawing frames in a mill and were operated spinning and drawing both cotton and rayon fibers.

Cot A, after 24 weeks of operation in spinning, continued to perform satisfactorily. In drawing, the cots began eyebrowing after 156 hours.

Cot B, after 24 weeks of operation in spinning, continued to operate satisfactorily with cotton, but began to eyebrow with rayon. In drawing, the cots began to eyebrow after 29 hours.

Cot C, after 24 weeks of operation in spinning, continued to operate satisfactorily on both cotton and rayon. In drawing, after 286 hours of continuous operation, no signs of eyebrowing were observed.

The superior performance of cot C was clearly demonstrated.

In a further comparison, cots similar to cot C were run on a high speed experimental drawing frame run at speeds double those used in the mills, and tested for eyebrowing in drawing cotton and rayon fibers. Plain Perbunan cots without the ground shell and polyvinyl alcohol were also run, along with Perbunan cots containing 50 parts by weight of ground cork per 100 parts of rubber. The plain Perbunan cot began to eyebrow after 15 minutes of operation, the cork-containing cots began to eyebrow after hours, while the ground shellpolyvinyl alcohol cots were continuing to run without eyebrowing after 120 hours.

I claim:

1. A textile fiber drafting cot having a working surface composed of a vulcanized oil-resistant synthetic rubberlike material having intimately incorporated therewith discrete particles of polyvinyl alcohol and particles of the soft, porous and fibrous shells of a nut-like material, to effect modification of the drafting properties thereof.

2. A cot according to claim 1 wherein the shell particles are ground up peanut shells.

3. A cot according to claim 2 wherein the synthetic rubber-like material is a butadiene-acrylonitrile copolymer.

4. A textile fiber drafting cot according to claim 3 wherein the synthetic rubber-like material is a polychloroprene.

5. A textile fiber drafting cot having a working surface composed of a vulcanized oil-resistant synthetic rubber-like material having intimately incorporated therewith from about 10 to about parts by weight of discrete particles of polyvinyl alcohol per 100 parts of a synthetic rubber-like material and from about 10 to about 100 parts by weight of particles of the soft, porous and fibrous shells of a nut-like material per 100 parts of the synthetic rubber-like material by weight.

6. A textile cot according to claim 5 wherein the synthetic rubber-like material is a butadiene-acrylonitrile copolymeri References Cited in the fileof this patent UNITED STATES PATENTS 2,304,656 Rockofi Dec. 8, 1942 2,373,698 McGeary Apr. 17, 1945 2,414,803 DAlelio Jan. 28, 1947 2,450,410 Baymiller Oct. 5, 1948 2,482,237 Berglund Sept. 20 1949 2,570,935 Frcedlander Oct. 9, 1951 2,645,587 Williamson July 14, 1953 FOREIGN PATENTS 15,988 Great Britain of 1915 511,489 Great Britain Aug. 18, 1939 579,083 Great Britain July 23, 1946 643,764 Great Britain Sept. 27, 1950 1,000,963 France Oct. 17, 1951 

1. A TEXTILE FIBER DRAFTING COT HAVING A WORKING SURFACE COMPOSED OF A VULCANIZED OIL-RESISTANT SYNTHETIC RUBBERLIKE MATERIAL HAVING INTIMATELY INCORPORATED THEREWITH DISCRETE PARTICLES OF POLYVINYL ALCOHOL AND PARTICLES OF THE SOFT, POROUS AND FIBROUS SHELLS OF A NUT-LIKE MATERIAL, TO EFFECT MODIFICATION OF THE DRAFTING PROPERTIES THEREOF. 